Favorites icon (favicon) file is placed in a web server root directory. It is a page icon or associated with a particular website. For example when you visit our site you see favicon in the browser’s URL bar, next to the site’s name. Also it appears next to the site’s name in lists of bookmarks, and next to the page’s title in a tabbed document interface.

There is a tool called ppmtowinicon which convert 1 or more portable pixmaps into a Windows .ico file You need to specify one or more portable pixmaps as input and it produces a Microsoft Windows .ico file as output. A Windows icon contains 1 or more images, at different resolutions and color depths. Microsoft recommends including at least the following formats in each icon (size and bits-per-pixel): => 16 x 16 – 4 bpp => 32 x 32 – 4 bpp => 48 x 48 – 8 bpp

How to create a favicon.ico with GIMP

You need to install netpbm – a graphics conversion tools under Linux / UNIX. You also need GIMP – the GNU Image Manipulation program to create a favicon on Linux.